A dark, narrow tunnel that leads to a charming lake and waterfall.

Known to backpackers as the "Steps of Doom," this walkway carved into the side of a seaside cliff leads to the Roman Tombs.

This balancing rock is one of Utah's most unusual geological formations.

Located more than 600 feet beneath the North Atlantic seabed, this tunnel boasts the world's first undersea roundabout.

Built in France in the 1400s, this gothic chapel now resides at Marquette University in Milwaukee, Wisconsin.

A strange collection of sculptures resides along a trail in Nova Scotia.

This log house sits in the remote Canadian wilderness, and holds a mysterious tale of the trapper who built it.

Graffiti, cars, and religion combine to create this jungle of scrap in the Nevada desert.

Visit a prison tower used during witch tribunals.

A Route 66 filling station that was designed to resemble the Hagia Sophia, and is now the symbol of an arts district.

A centuries-old quest to create artificial life is alive and well in the French town of Limoux.

Grab a latte at the birthplace of modern American skateboarding.

A giant scrap metal troll rests his hands on top of a dilapidated building covered in graffiti.

The site of an early Arthurian battle and the dwelling-place of prehistoric people and (possibly) an ancient race of giants.

Structure built from the skulls of vanquished foes.

This Hungarian stilt village is built in a lake that never freezes over due to the power plant that that uses it as a cooling pond.

Unruly residents were housed in this one-person cell until the Black Maria arrived.

Take a ride back in time with a steam locomotive trip through Eritrea’s mountainous countryside.

In the heart of Luxembourg's "little Switzerland" weaves a breathtaking natural sandstone canyon with a mythological past.

Only 68 people per day are allowed to visit this New Zealand bird-watcher’s paradise.

Where Kevin Eastman and Peter Laird created their "heroes in a half shell" and founded Mirage Studios.

Crumbling remnant of Rio's colonial past tucked behind Corcovado mountain in the neighborhood of Cosme Velho.

There's light and a dreamlike panorama at the end of this tunnel.

This 317-ton walkable art installation is an homage to Korea's "City of Steel."